1. Field of the Invention
The present invention relates to methods for preparing food products, and, more particularly, to such a method for preparing a food product from citrus fruit.
2. Description of Related Art
Additional uses for foods are often sought in order to enhance a product""s desirability and marketability. Such foods include produce, namely, citrus fruits. Consumer demand for freshness and convenience has generated interest in minimally processed citrus products, including individually separated juice vesicles.
In the past, mechanical techniques have been known to separate fresh juice vesicles by cutting and rotating devices (U.S. Pat. No. 2,510,679). Such techniques tend to rupture the tender juice sacs, leaving a less desirable product. Stephenson (U.S. Pat. No. 1,731,476) teaches freezing fruit and then crushing it to break apart the peel and the remainder of the fruit, thereby separating the peel from the remainder of the fruit. The apparatus of Ifuku et al. (U.S. Pat. No. 4,294,861) cuts the fruit into pieces and uses fluid under pressure to separate the sacs. Ando (U.S. Pat. No. 4,738,194) discloses immersing the fruit in a cryogen, crushing the frozen fruit, and separating the juice sacs from the rest of the fruit. Kolodesh et al. (U.S. Pat. No. 4,873,106) disclose cutting fruit in half and then coring the fruit halves. A rotating screen through which juice sacs pass separates the sacs from the rest of the fruit.
Chemical separation techniques have also been applied (U.S. Pat. Nos. 4,139,651 and 4,560,572) for reducing the force required to achieve separation. The method of Webster et al. (U.S. Pat. No. 3,246,993) includes peeling the fruit, immersing the fruit in a cryogen, performing thermal shock freezing, removing the frozen fruit from the cryogen, and separating out the juice cells by agitation.
The drawbacks of the previous methods known in the art include loss of flavor, expense associated with complex apparatus, and loss of vesicle integrity.
It is therefore an object of the present invention to provide a method and system for separating intact citrus juice vesicles from citrus fruit.
It is a further object to provide such a method and system that have improved efficiency.
It is another object to provide such a method and system that do not require peeling of the fruit.
It is also an object to provide such a method and system that have superior flavor retention.
It is an additional object to provide such a method and system that use essentially neither acid nor alkali.
A further object is to provide a method that also yields high-quality usable byproducts.
These and other objects are achieved by the present invention, a method for separating juice vesicles from a citrus fruit. The method comprises the step of forming a plurality of generally circumferential scores between a stem end and a stylar end of a citrus fruit. Preferably each score extends at least through a flavedo of a peel of the fruit. Next the fruit is cut into a plurality of slices in a direction normal to a longitudinal axis defined by the stem end and the stylar end. The slices are then frozen, and an impulsive force is applied to the slices to form a plurality of fruit components. These fruit components comprise juice vesicles and other fruit components, such as the peel, connective membranes, and seeds. The juice vesicles are then mechanically separated from the other fruit components.
The features that characterize the invention, both as to organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description used in conjunction with the accompanying drawing. It is to be expressly understood that the drawing is for the purpose of illustration and description and is not intended as a definition of the limits of the invention. These and other objects attained, and advantages offered, by the present invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawing.